Enhanced dissolution of sildenafil citrate as dry foam tablets

Abstract

Dry foam formulation technology is alternative approach to enhance dissolution of the drug. Sildenafil citrate was suspended in sodium dodecyl sulfate solution and adding a mixture of maltodextrin and mannitol as diluent to form a paste. Sildenafil citrate paste was passed through a nozzle spray bottle to obtain smooth foam. The homogeneous foam was dried in a vacuum oven and sieved to obtain dry foam granules. The granules were mixed with croscarmellose sodium, magnesium stearate and compressed into tablet. All formulations were evaluated for their physicochemical properties and dissolution profiles. All the tested excipients were compatible with sildenafil citrate by both differential scanning calorimetry (DSC) and infrared (IR) analysis. There are no X-ray diffraction (XRD) peaks representing crystals of sildenafil citrate observed form dry foam formulations. The hardness of tablets was about 5 kg, friability test <1% with a disintegration time <5 min. The sildenafil citrate dry foam tablet had higher dissolution rate in 0.1 N HCl in comparison with commercial sildenafil citrate tablet, sildenafil citrate prepared by direct compression and wet granulation method. Sildenafil citrate dry foam tablet with the high-level composition of surfactant, water and diluent showed enhanced dissolution rate than that of the lower-level composition of these excipients. This formulation was stable under accelerated conditions for at least 6 months.

Keywords:

• Sildenafil citrate
• dissolution
• dry foam tablet
• drug release

Acknowledgements

The authors would like to thank pharmacy students (Mr. Punnut Pattaranutaporn, Mr. Pichaipong Yodrabum, and Ms. Patcharaphon Namjaitaharn) who helped in some parts of the experiments in a senior project.

Disclosure statement

The authors report no conflicts of interest. The authors alone are responsible for the content and writing of this article.

Additional information

Funding

The authors acknowledge the financial support from Walailak University (Grant Number WU57209), Drug and Cosmetic Research and Development Unit and Research and Development Division, School of Pharmacy, Walailak University.